Radio transmitting system



June 24, 1930. F. A. KOLSTER 1,761,245

unto 'rnmsuxwme sYs'rzI Filed May 23. 1925 Mada/am; acv/Ee mvmros WWATTORNEY Patented June 24, 1930 UNITED STATES PATENT oF icE nnnnnnrcx A.KonsTER, on PALO ALTO, cnmnonnm, 'nssrenon To FEDERAL TELEGRAPH COMPANY,OF CALIFORNIA Application filed May 533,

My invention relates to the simultaneous transmission of a plurality oftelegraphic or telephonic signals or. messages represented byelectro-radiant energies in radio systems, or by carrier Wave currentsin "conductor systems, utilizing different frequenciesderived from asingle oscillatory source, one or more-of the frequencies beingharmonics of the fundamental oscillations produced by the oscillator andone ofthe signals or messages being represented-by electro-rac liz intenergy of thefundamental frequency of. the oscillations produced by theoscillator.

In accordance with my invention, electro radiant energy of thefrequencies of the fundamental frequency of oscillations may beutilized, and one or morelharmonics of the fundamental frequency. is orare reinforced and amplified and utilized for transmission of one ormore separate and distinctsignals or messages. 7 a 1 Furtherinaccordance with myinvention, there are coupled With the inductance ofan oscillatory circuit traversed by oscillations of fundamentalfrequency one ormore circuits tuned to the desired harmonic-orharmonics, and With each tuned circuit is asso- V ciated suitableamplifying -apparatus, as a scribed.

thermionic amplifier or a plurality ofithem in staged relation, withmeans for impressing the amplified harmonicupon a'radiating or carrierwave conducting system; and further in accordance .Wliill my invention,a system for radiating or conducting the energy at the fundamentalfrequencyniay also be coupledto the circuittraversed by oscillations offundamental frequency.

My, invention resides in. a method and system of the characterhereinafter de- For an understanding of my method and for anillustration of various forms my apparatus may take, reference is to behad to the accompanying ,drawing, in which:

tem for transmitting both fundamental and harmonic frequencies derivedfrom oscillationsproducedby an arc. r v 1 Fig. 2, is a fragmentary.diagram of a1 modification Wherein'a thern'iionic oscilla-' inginductance L SAN sRANcIsoo, 'cnnrronnm, A CORPORATION or nAnIoTRANSMITTING sY'sTEr/r" 1925. semi no; 32,3 0.

tor is utilized in lieu of the arc of Fig. 1.

Referring to Fig. 1, G represents a suitable source ofcurjrent, as, forexample, a dynamo-electric generator supplying direct current throughthe high frequency choke coils f, f. to the electrodes P and Nof an arcin shunt to Which are connected thein ductance or common primary L andthe condenser C, In; thecircuit L, C will be produced" free:oscillations of fundamental frequencyv dependent practicallyupontheprod: not of the inductance L by the capacity, of-

the condenser C Coupled to the common primary or inductance is thesecondary S connected through-condenser C to earth or ,counter-capacltyE and to the :koy K,

V. which when depressed engages the contactrls to bring intocommunication with the secondary S theradiating antenna A provided, ifsuitable or desirable, With the loadsiti on mentioned, there will beradiated sustained high frequency'energyof'the fundamental frequencyproduced by the arc. NVhen the key. .israised into; engagement with theupper contact k there is brought duct-ance L condenser C and resistanceR, representing a combination of resistance, ca-v pacity and inductancecorresponding to that of the antenna A and'itsinductance L, the keybeinga-t a position'of potential node inthesystem.

Coupled ,to i the common primary or inductance L is the" secondary :S,shunted by the tuning condenser C for tuning the circuit to a suitableharmonic of the funda- Nith the key in the I .into circuit with thesecondary S the inmental 'frequency.. Assuming the; fundaby thethermionic amplifier vV, \vhose anode p circuit is coupled to theantenna A which n Fig. 1 1S a dlagrammatlc vlew of a sys-' radiatesenergy of thesixth harmonic frequency, the antenna A being attuned toSimilarly, the antennas A and A tuned, respectively, to other harmonics,as, for example, the tenth and thirtieth harmonics, respectively, aresupplied by reinforced and amplified harmonics whose energy is derivedfrom the circuit L, C and in which circuit these harmonics arereinforced by the tuned grid circuits of the thermionic amplifiers V andV comprising with the tube V the secondary S and tuning con denser C andfor the tube V the secondary S shunted by the tuning condenser C In thegrid lead of each of'the tubes V, V and V may be connected suitable keymechanisms K K and K respectively, for controlling the radiated energyin accordance with telegraphic signals.

Obviously, however, in lieu of one or more or all ofthe telegraphic keys1Q, K K there may be used microphone transmitters controlling thepotentials of the grids of the respective tubes in well known manner,whereby with differentharmonics, reinforced and amplified, severaldifferent telephonic messages may be simultaneously transmitted, andsimultaneously the fundamental may be utilized for transmitting throughthe instrumentality of the antenna A To prevent energy in any of theantennas A A or A reacting uponthe anode circuit of the associatedamplifier tube, and theret-hrough upon the grid circuit and/or throughthe grid circuit upon the circuit 'L, C, the anode circuit is notconnected directly to the cathode of the tube, but at a suitable pointin the secondary 8*, S or S*, thereby rendering the anode circuitelectrically symmetrical with respect to the input or grid circuit,preventing the reverse energy flow described, and preventing productionof individual oscillations by each of the vacuum tubes.

lVhile in Fig. 1 an arc oscillator is shown, it will be understood thatany other type of oscillator may be utilized, as, for example, athermionic oscillator, as indicated in Fig. 2, which illustrates anoscillator of well known type producing free oscillations by means ofthe thermionic tube V in whose anode circuit is a port-ion of theinductance L and in whose grid circuit is the remainder thereof, withthe condenser C connected across the terminals of the entire inductanceL. Coupled to the common primary or inductance L are the aforesaidsecondaries S S, related, as described in connection with Fig. l, withthe several antennae A 'A*.

In the caseof both Fig. 1 and Fig. 2, it will be found desirableproperly to locate the secondaries S S and S with respect to each.ot'heralong the common primary or inductance L. In general, eachsecondary should. be located at such region along the inductance L thatthere occurs thereat a curwere divided into sections, one foreachsecondary El -8 and with greater distributed capacity the production,reinforcement and amplification of harmonics is facilitated. It will beunderstood, however, that as regards the broader aspects of my inventionthe inductance L may be comprised of separate serially connectedprimaries inductively related, respectively, to the secondaries S, S.lVhile I have more particularly referred to the impression of energiesof different frequencies upon antennas or radiating structures, forradio systems, it will be understood that inlieu of such antennae theremay be utilized conductors extending between transmitting and receivingstations, as in carrier wave telephony, telegraphy and the like.

\Vhat I claim is:

1. The method which comprises producing current of fundamental radiofrequency, effecting How of the unamplified current in a current path,reactively coupling to said path-a circuit resonant to a harmonic ofsaid fundamental frequency to encourage development of oscillations ofsaid harmonic frequency in said path, controlling the current offundamental frequency to represent a signal or message, controlling theoscillations of harmonic frequency to represent. a clifferent signal ormessage, and impressing upon the natural media disassociatedelectroradiant energies having, respectively, said fundamental andharmonic frequencies.

2. The method which comprises correlating an arc with capacity andinductance to effect production of oscillations of fundamental andharmonic frequencies selecting therefrom oscillations of harmonicfrequency, individually controlling the oscillations of fundamental andharmonic frequencies to represent different signals or messages,amplifying the energy of harmonic frequency, impressing upon the naturalmedia electroradiant energy of the amplified harmonic path to saidinductance.

monic frequency with respect toreverse energy flow to a path traversedby'o'scillations" o'fs aid fundamental frequency. Q s s f 4.- The methodwhich comprises cor'relah ing an arc with capacity and inductance to eflectproduction of oscillationsfof vfundamental frequency, derivingtherefromoscil lations of harmonic frequency, "amplifying saidoscillations of Lharmomc frequency, transmitt ng a signal or messagerepresented by the oscillations of harmonic"frequency,

by the oscillations er harmonic frequency,

means for abstracting fromlsaid inductance at a different reg onthereofbsc llations of another frequency, said different region beinganti-nodal with respect to current cf said other frequency, and meansfor transmitting signals or messages represented by the oscil; lationsof said other frequency. 1

6. Transmitting apparatus "comprising means associated with capacity andinductance to .produce free oscillations of fundamental frequency, meansresonant to a harmonic frequency for reinforcing in said inductanceoscillations of saidharmonic frequency, means for transmitting asignalor message represented by. theoscillations of harmonic frequency,and means for preventing reverse energy flow froma transmitting 7,Transmitting apparatus means associated With capacity and induc fame toproduce free oscillations of'funda mental frequency, means resonant to aharmonic frequency for, reinforcing in said inductance oscillations; ofsaid harmonic frequency, said inductance having characteris-vt-icscausing accentuation therein of oscilla tions of harmonicfrequency, meansfor am'- plifying the oscillations of harmonicfrequency, and means for transmitting a si -V na-l or messagerepresented by the oscillations ofharmonic frequency.-.

" 8. Transmittin'f apparatus comprising an arc, inductance and capacityrelated toproduce oscillations .of fundamental,frequency,

said inductance having characteristiCs causing accentuation therein,of,oscillationsl of har nonic frequency, means for transmittingcomprising 7 a signalor message represented by the os-. cillations ofharmonic frequency, means for abstracting from said inductanceoscillations of fundamental frequency, and means fortransmittlngsignalsor messages represented j by sa d oscillatlons offundamental fre-' qu n' r a 9; Transmitting apparatus comprising an arc,inductance and capacity related to produce oscillations of fundamentalfrequency, means resonant to a harmonic frequency for reinforcing saidinductance oscillations of said'harmonic frequency, means fortransmitting a signal or ines sage represented by the oscillations of]harmonic frequency, means for abstracting from said inductanceoscillations of fundamental frequency, means for -transmittingsignalsor' messages represented y d oscillations of fundamental frequency, andmeans for preventing reverse energy flow from a transmitting path tosaid inductance. 1

i 10. Transmitting apparatus'comprising an arc, inductance and capacityrelated to produce oscillations of fundamental frequency,

said inductance having characteristics causing accentuation therein of'oscillations of harmonic "frequency, means resonant to harmonicfrequency for reinforcing insaid nductance oscillations of said harmonicfife quency, meansfor amplifying'the oscillations of harmonic frequency,means for transmitting asignal or message represented by theoscillations of harmonic frequency,"

means fdr abstracting from said inductance oscillationsflof "fundamentalfrequency, and 7 means for transmitting signals or messages representedby said oscillations of funda mental frequency at substantiallyltheiroriginal amplitude.

11. Transmitting apparatus comprising Vmeans for producing current offundamental radio frequency in a circuit," ai'tuned circuit coupledtosaid'first circuit to'promote there in f and derive therefromoscillations of harmonic frequency, means individually controlling theoscillations of fundamental and har-; monic frequenciesto representdifferent signals ormessages, and means for impressing s upon thenatural media disassociated electroradiant energies having,respectively, "said fundamental and harmonic frequencieslcomprisingindependent antenna structures.

12. Transmitting apparatuscomprising an arc, capacity. and inductance Iassociated therewith to'efi'ect production of oscillations offundamental and harmonic 'frequenc'ies,

. means selecting therefrom oscillations of harmonic frequency, meansindividually con-' trolling the oscillations of fundamental and harmonicfrequenciestorepresent different.

signals or messages and means for, impressing upon the naturalmediaelectr'o-radian't energies having, respectively, said funda mental andharmonic frequencies;

l3. Transmitting apparatus comprising an arc, capacity and inductanceassociated therewith to effect production of oscillations of fundamentaland harmonic frequencies, means directly selecting therefromoscillations of harmonicfrequency, means individually controlling theoscillations 'of fundamental and harmonic frequencies to representdiiferentsignals or messages, means for amplifying the energy ofharmonic frequency, means for impressing upon the natural mediaelectro-radiant energyof the amplified harmonic frequency, and means forimpressing upon the natural media electroradiant energy of saidfundamental frequency at substantially its original amplitude.

14. Transmitting apparatus comprising inductance and capacitycorrelatedto effect production of free oscillations of fundamental andharmonic frequencies,transmitting circuits resonant to the fundamentaland harmonic frequencies, means for magnetically coupling thetransmitting circuits'to the inductance to permit transfer ofoscillations of selected frequency from the inductance through thetransmitting circuits, and means preventing the production of sustainedfree oscillations in the transmitting circuits. 1

15. Transmitting apparatus comprislng means associated with capacityandflinductance to produce free oscillations of fundamental frequency, aresonant circuit, forabstracting oscillations of harmonic frequency fromsaid inductance, a signaling circuit for utilizing said harmonicfrequency oscillations, and a symmetrical connection between saidsignaling circuit and the resonant circuit arranged to preventthe'feedback of harmonic frequency to said inductance. q i

16. Transmitting apparatus comprising means associated with capacity andinductance to produce free oscillations of fundamental frequency,amplifying means resonant to a harmonic frequency comprising an inputcircuit magnetically coupled to said inductance and an output circuitnormally in energy transfer relation to said input circuit, and meansfor controlling the extent of such energy transfer in order to preventthe production of individual oscillations in said amplifying means. 17.Transmitting apparatus comprising means associated with capacity andinductance to produce free oscillations of fundamental frequency, acircuit resonant to a harmonic frequency magnetically coupled to saidinductance, an amplifier comprising an input circuit connected acrossthe resoof individual oscillations in said amplifier are prevented,

18. Transmitting apparatus comprising a circuit including inductance andcapacity correlated to effect production of oscillations of fundamentaland harmonic'frequencies, a transmitting circuit magnetically coupled tosaid first named circuit and abstracting therefrom oscillations ofharmonic frequency, 'a transmitting medium, a thermionic amplifier ofthe three electrode type intervening between said transmitting circuitand transmitting medium, and a symmetrical connection between the outputand input circuits of said amplifier.

19. Transmitting apparatus comprising a circuit including inductance andcapacity correlated to effect production of oscillations of fundamentaland harmonic frequencies, a transmitting circuit magnetically coupled tosaid first named circuit and abstracting therefrom oscillations ofharmonic frequency, a transmitting medium, a thermionic amplifier of thethree electrode type intervening, between said transmitting circuit andtransmitting medium, a symmetrical connection between the output andinput circuits of said amplifier, and means for rendering the inputcircuit of said amplifier resonant to said harmonic frequency.

20. Transmitting apparatus comprising a circuit including an arc andcorrelated inductance and capacity for'the production of oscillations offundamental and harmonic frequencies, a structure for radiating energyof the fundamental frequency at substan-' tially its original amplitude,means for controlling the energy of fundamental frequency to represent asignal or message, a second structure radiating energy of harmonicfrequency, a thermionic amplifier of the three electrode type havinginput and output circuits and intervening between said first namedcircuit and said second radiating structure, a magnetic coupling betweenthe input circuit of said amplifier and said first named circuit, andmeans intervening between said coupling and said thermionic amplifierrendering the circuit resonant to said harmonic frequency.

21. Transmitting apparatus comprising an arc, capacity and inductanceassociated therewith to effect production of oscillations of fundamentaland harmonic frequencies, means directly selecting therefromoscillations of harmonic frequency, means individually controlling the.oscillations of fundamental and harmonic frequencies to representdifferent signals or messages, and means comprising independent antennastructures for impressing upon the natural media disassociatedelectro-radiant energies having, respectively, said fundamental andharmonic frequencies. I

22. The method which comprises correlat- .quencies.

In testimony whereof I have hereunto aifixed my signature this 19th dayof May,

FREDERICK A. KOLSTER.

